Which round has a gilding metal-jacketed lead alloy core bullet with a steel penetrator?

The correct choice is based on the key characteristics of the M855 round, which is known for its specific composition intended for enhanced performance. The M855 is a 5.56x45mm NATO cartridge that features a gilding metal jacket, which is typically made of copper, that encases a lead alloy core. Crucially, this round is designed with a steel penetrator, which enhances its capability to penetrate various types of armor and hard targets compared to standard lead projectiles.

This combination of materials allows the M855 to provide improved performance over its predecessors, making it effective in military applications where armor penetration is necessary. Understanding the specifications of different ammunition types is essential for security forces in order to select the right round for their operational needs. In contrast, the other options feature different designs and purposes, which do not include the specific combination of a gilding metal jacketed lead alloy core with a steel penetrator found in the M855.